All study participants will undergo screening evaluations to determine eligibility for the study. All screening evaluations must be performed within 28 days of pacritinib dosing (Day 1). Assignment of patients to each hepatic impairment group will be defined by Child-Pugh Clinical Assessment Score at the time of Screening. Group 3 patients will not be dosed until at least 2 patients combined from Groups 1 and 2 have completed the study (Day 8). Healthy subjects will be enrolled after hepatic impairment accrual is complete to allow for age-, gender- and body mass index- (BMI) matching with the hepatic impairment population. Participants will be admitted to the study site on Day -1 (i.e., Check-in). On Day 1, upon receipt of all baseline safety evaluation results and confirmation of eligibility, study participants will be administered a single dose of 400 mg pacritinib orally under fasting conditions. Fasting will start 10 hours prior to pacritinib administration and continue for an additional 4 hours after administration. Following administration of pacritinib, participants will remain confined to the study site for 168 hours (8 days) after pacritinib dosing for collection of blood for PK and safety assessments.